Compact Nikon binoculars are the handiest and most versatile of all optical instruments I have used. Any stain or mark on the surface of a binocular lens tends to scatter light, thereby producing low-contrast viewing.
Binoculars are just more comfortable to look through and hold steady because both hands are usually used. As an experienced wildlife photographer my top priority was optical quality, and I did alot of research before deciding on this pair. Most pocket binoculars have multi-coated lenses and high-refraction prisms.
Folding in the eyepiece between observations will protect the eyepiece against scratches or other inadvertent damage. Remember you get what you pay for, so ensure you buy a good quality pair to prevent disappointment in the field. You can see so much detail in the craters, one which you can not see by plainly looking at the moon with the naked eye.
Magnification over ten generally causes the binoculars to lose some image crispness. Night vision binoculars are very comfortable to use because we are accustomed to seeing with both eyes, but they are pricey. Roof prism binoculars are so much easier to water and fog proof because of internal focusing.
As you can see from this article, the best binoculars repair strategy is preventive. When you travel, bring your binoculars, they will not add measurable weight to your luggage.